(a) a-particles
(b) Neutrons
(c) Electrons
(d) Protons
Answer:
Radioactivity was discovered by
(a) H. Becquerel
(b) M. Curie
(c) J.J. Thomson
(d) W. Roentgen
Answer:
Isotopes have the same
(a) Mass number
(b) Avogadro's number
(c) Atomic number
(d) None of these
Answer:
Curie is a unit of
(a) Intensity of gamma rays
(b) Radioactivity
(c) Energy of gamma rays
(d) Half-life
Answer:
The strongest force in the nature is
(a) Magnetic force
(b) Nuclear force
(c) Electric force
(d) Gravitational force
Answer:
Energy is continuously generated in the sun due to
(a) Artificial radioactivity
(b) Radioactivity
(c) Nuclear fusion
(d) Nuclear fission
Answer:
The process of emission of electrons from metal by UV rays is
(a) Secondary emission
(b) Field emission
(c) Photoelectric emission
(d) Thermionic emission
Answer:
When the temperature of semiconductor is increased, its electrical conductivity
(a) Decreases
(b) Increases
(c) Remains the same
(d) None of these
Answer:
An oscillator is nothing but an amplifier with
(a) Negative feedback
(b) No feedback
(c) Positive feedback
(d) Large gain
Answer:
The electrical circuit used to get smooth DC output from a rectifier circuit is called
(a) Oscillator
(b) Full rectifier
(c) Amplifier
(d) Filter
Answer: